Spectroscopic device, Raman spectroscopic measuring device and spectroscopic method

Abstract

A spectroscopic device 5 receives light L1, which is wavelength-resolved in a predetermined direction, through a spectroscopic optical system 4, which includes a spectroscopic element for acquiring spectroscopic spectral data of the light L1, and the spectroscopic device includes: a CCD imaging element 9 with a pixel unit 11, which contains a plurality of pixels 21 arranged in a row direction along a wavelength resolution direction of the light L1 and in a column direction perpendicular to the row direction, an accumulation unit 12, which is arranged for each column at an end section in the column direction of the pixel unit 11 and accumulates charges generated in pixels 21 of each column, and a readout unit 13, which outputs an electrical signal of each column corresponding to a magnitude of the charge accumulated in the accumulation unit 12;a semiconductor element 10 that converts the electrical signal of each column into a digital signal and outputs the digital signal; and a generating unit 15 that generates spectroscopic spectral data 32 based on the digital signal.

Description

Technical field

[0001] The present disclosure relates to a spectroscopic device, a Raman spectroscopic measuring device and a spectroscopic method. background

[0002] A conventional spectroscopic device is, for example, one described in patent literature 1. This conventional spectroscopic device is a so-called Raman spectroscopic device. The spectroscopic device comprises a device for the linear irradiation of excitation light, a movable stage on which a sample is placed, an objective lens that focuses Raman light from an excitation light irradiation area, a slit provided at an imaging position of the Raman light, a spectroscope that scatters light passing through the slit, a CCD detector that acquires an image of the Raman spectrum, and a control device that controls the imaging measurement by synchronizing between the movable stage and the CCD detector. Citation list for patent literature

[0003] Patent literature 1: Unexamined Japanese patent publication no. 2016-180732 Summary of the invention: Technical problem

[0004] In the field of spectroscopic measurements such as Raman spectroscopy, fluorescence spectroscopy, and plasma spectroscopy, vertical binning of a CCD image sensor is used to acquire spectroscopic data and improve the signal-to-noise ratio (SNR) of a signal. During vertical binning in a CCD image sensor, the charges generated in each pixel are added for multiple stages. In a CCD image sensor, readout noise is generated only in the final amplifier stage and does not increase with vertical binning. Therefore, the SNR of the signal can be improved by increasing the number of vertical binning stages.

[0005] Besides CCDs, CMOS image sensors are also known as image sensors. However, CMOS image sensors are not yet widely used in the field of spectroscopic measurement. In a CMOS image sensor, an amplifier is located in each pixel, and a charge is converted into a voltage for each pixel. When performing vertical binning with a conventional CMOS image sensor, the problem arises that the readout noise is also integrated with an increasing number of vertical binning steps, resulting in a lower signal-to-noise ratio (SNR) compared to using a CCD image sensor.

[0006] The present disclosure was made to solve the above problems, and one objective of it is to provide a spectroscopic device, a Raman spectroscopic measuring device and a spectroscopic method capable of acquiring spectroscopic spectral data with an excellent SN ratio. Solution to the problem

[0007] The basic concept of a Raman spectroscopic measuring device and a spectroscopic method according to one aspect of the present disclosure is as described in the following [1] to

[10] .

[0008] A spectroscopic device receiving wavelength-resolved light in a predetermined direction through a spectroscopic optical system containing a spectroscopic element for acquiring spectroscopic spectral data of the light, the spectroscopic device comprising: a CCD-type imaging element comprising: a pixel unit with a plurality of pixels arranged in a row direction along a wavelength-resolving direction of the light and in a column direction perpendicular to the row direction, an accumulation unit arranged for each column at an end section in the column direction of the pixel unit and accumulating charges generated in pixels of each column, and a readout unit outputting an electrical signal for each column corresponding to the magnitude of the charges accumulated in the accumulation unit; a semiconductor element.that converts the electrical signal output by the readout unit of each column into a digital signal and outputs the digital signal; and a generation unit that generates spectroscopic spectral data based on the digital signal output by the semiconductor element.

[0009] In this spectroscopic device, wavelength-resolved light is received by a multitude of pixels arranged in the row and column directions. Charges generated in the pixels of each column are accumulated, and then an electrical signal corresponding to the magnitude of the charges is output for each column. Since these operations are performed by the CCD imaging element, the increase in readout noise during the reading of the charges generated in the pixels of each column can be avoided. Furthermore, the readout speed when outputting the digital signal based on the electrical signal of each column is faster than when using a horizontal transmission circuit, and noise caused by heat generation is also suppressed.Therefore, in this spectroscopic device, spectroscopic spectral data can be acquired with an excellent SN ratio.

[0010] The spectroscopic apparatus described in [1], wherein the imaging element comprises: a first pixel unit and a second pixel unit divided in the column direction, a first accumulation unit and a second accumulation unit, wherein the first accumulation unit is arranged for each column at an end section in the column direction of the first pixel unit and accumulates charges generated in pixels of each column, and the second accumulation unit is arranged for each column at an end section in the column direction of the second pixel unit and accumulates charges generated in pixels of each column, and a first readout unit and a second readout unit, wherein the first readout unit outputs a first electrical signal corresponding to a magnitude of the charges accumulated in the first accumulation unit, and the second readout unit outputs a second electrical signal,which corresponds to the magnitude of the charges accumulated in the second accumulation unit, and the semiconductor element contains a first conversion unit that converts the first electrical signal of each column output by the first readout unit into a digital signal and outputs the digital signal, and a second conversion unit that converts the second electrical signal of each column output by the second readout unit into a digital signal and outputs the digital signal. In this case, the first pixel unit and the second pixel unit can be used selectively according to the mode of the spectroscopic spectral image. Therefore, spectroscopic spectral data of different types of light can be acquired with a favorable SN ratio.

[0011] The spectroscopic device described in [2] has a first exposure time for each pixel belonging to the first pixel unit that is shorter than a second exposure time for each pixel belonging to the second pixel unit. According to this configuration, for example, spectroscopic images of light with different intensities depending on the wavelengths can be acquired at different exposure times in the first and second pixel units. By combining a saturation wavelength band of spectroscopic data acquired with a short exposure time in the first pixel unit and a non-saturation wavelength band of spectroscopic data acquired with a long exposure time in the second pixel unit, spectroscopic data with a favorable S-N ratio can be acquired in a high dynamic range.

[0012] The spectroscopic device described in [3], wherein image data of a plurality of frames in the first pixel unit are acquired during a period in which image data of one frame in the second pixel unit are acquired. In this case, the readout noise of the pixels in each column between the first and second pixel units can be unified, even if different exposure times are set for the first and second pixel units. Therefore, the SN ratio of the spectroscopic spectral data can be stably improved.

[0013] The spectroscopic apparatus described in [1], wherein the imaging element comprises: a first pixel unit and a second pixel unit divided in the row direction, a first accumulation unit and a second accumulation unit, wherein the first accumulation unit is arranged for each column at an end section in the column direction of the first pixel unit and accumulates charges generated in pixels of each column, and the second accumulation unit is arranged for each column at an end section in the column direction of the second pixel unit and accumulates charges generated in pixels of each column, and a first readout unit and a second readout unit, wherein the first readout unit outputs a first electrical signal corresponding to a magnitude of the charges accumulated in the first accumulation unit, and the second readout unit outputs a second electrical signal,which corresponds to the magnitude of the charges accumulated in the second accumulation unit. In this case, the first pixel unit and the second pixel unit can be used selectively according to the mode of the spectroscopic spectral image. Therefore, spectroscopic spectral data from different types of light can be acquired with a favorable SN ratio.

[0014] The spectroscopic apparatus described in [5], wherein the first readout unit outputs the first electrical signal of each column at a stage in which charges generated in pixels corresponding to a first number of rows are accumulated in the first accumulation unit, and the second readout unit outputs the second electrical signal of each column at a stage in which charges generated in pixels corresponding to a second number of rows, which is smaller than the first number of rows, are accumulated in the second accumulation unit. In this case, spectroscopic spectral data can be acquired with a favorable SN ratio in a high dynamic range, while the exposure time of each pixel belonging to the first pixel unit and the exposure time of each pixel belonging to the second pixel unit are kept equal to each other.

[0015] The spectroscopic device described in one of points [1] to [6] also includes an analysis unit that analyzes the spectroscopic spectral data. In this case, the spectroscopic device is equipped with a function for analyzing the spectroscopic spectral data, thus improving user convenience.

[0016] The spectroscopic device described in one of points [1] to [7], which also includes the spectroscopic optical system with the spectroscopic element. In this case, the spectroscopic device is provided with a wavelength resolution function of the light, thus improving convenience.

[0017] A Raman spectroscopic measuring apparatus comprising: the spectroscopic apparatus described in any one of points [1] to [8]; a light source unit generating light with which a sample is irradiated; and an optical light guidance system guiding Raman scattered light generated by irradiating the sample with the light to the spectroscopic apparatus.

[0018] In this Raman spectroscopic measuring device, wavelength-resolved Raman scattered light is received by the multitude of pixels arranged in the row and column directions. Charges generated in the pixels of each column are accumulated, and then an electrical signal is output for each column corresponding to the magnitude of the charges. Since these operations are performed by the CCD imaging element, an increase in readout noise when reading the charges generated in the pixels of each column can be avoided. Furthermore, the readout speed when outputting the digital signal based on the electrical signal of each column is higher than when using a horizontal transmission circuit, and noise caused by heat generation is also suppressed.Therefore, in this Raman spectroscopic measuring device, the spectroscopic spectral data can be acquired with an excellent SN ratio.

[0019] A spectroscopic method for receiving light that is wavelength-resolved in a predetermined direction in order to acquire spectroscopic spectral data of the light, wherein the spectroscopic method comprises: a light reception step of receiving the wavelength-resolved light by a plurality of pixels arranged in a row direction along a wavelength resolution direction and in a column direction perpendicular to the row direction; an accumulation step of accumulating charges generated in pixels of each column; a readout step of outputting an electrical signal of each column corresponding to a magnitude of the accumulated charges; a conversion step of converting the electrical signal of each column into a digital signal and outputting the digital signal; and a generation step of generating spectroscopic spectral data based on the digital signal.

[0020] In this spectroscopic method, wavelength-resolved light is received by a multitude of pixels arranged in the row and column directions. Charges generated in the pixels of each column are accumulated, and then an electrical signal corresponding to the magnitude of the charges is output for each column. This avoids an increase in readout noise when reading the charges generated in the pixels of each column. Furthermore, outputting the digital signal based on the electrical signal of each column increases the readout speed and suppresses noise caused by heat generation. Therefore, this spectroscopic method allows for the acquisition of spectroscopic data with an excellent signal-to-noise ratio. Advantageous effects of the invention

[0021] According to the present disclosure, the spectroscopic spectral data can be acquired with an excellent SN ratio. Brief description of the drawings Fig. Figure 1 is a block diagram showing a configuration of a Raman spectroscopic measuring device according to an embodiment of the present disclosure. Fig. Figure 2 is a schematic view that represents an example of a pixel unit. Fig. Figure 3 is a schematic diagram showing an example of spectroscopic spectral data acquired by a spectroscopic device. Fig. Figure 4 is a view showing the structure of an image sensor. Fig. Figure 5 is a view showing the structure of the image sensor. Fig. Figure 6 is a schematic cross-sectional view showing a peripheral structure of an accumulation unit. Fig. Figure 7 is a view showing the structure of a semiconductor element. Fig. Figure 8 is a view illustrating the structure of the semiconductor element. Fig. Figure 9 is a schematic view showing a relationship between an exposure time of each pixel belonging to a first imaging unit and an exposure time of each pixel belonging to a second imaging unit. Fig. Figure 10 is a flowchart illustrating a spectroscopic method according to an embodiment of the present disclosure. Fig. Figure 11 is a schematic view showing a pixel unit of a spectroscopic device according to one modification. Fig. Figure 12 is a diagram showing an example of a spectrum of light incident on the spectroscopic apparatus according to the modification. Fig. Figure 13 is a diagram showing an example of first spectral data and second spectral data acquired by the spectroscopic device according to the modification. Fig. Figure 14 is a diagram showing an example of spectral data derived from the in Fig. The first spectral data shown in the 13 images and the second spectral data were generated. Fig. Figure 15 is a schematic view representing a state of formation of a spectroscopic spectral image in the spectroscopic device according to the modification. Description of the embodiments

[0022] Preferred embodiments of a spectroscopic device, a Raman spectroscopic measuring device and a spectroscopic method according to one aspect of the present disclosure are described in detail below with reference to the drawings.

[0023] Fig. Figure 1 is a block diagram showing a configuration of a Raman spectroscopic measuring device according to an embodiment of the present disclosure. A Raman spectroscopic measuring device 1 is a device for measuring the physical properties of a sample S using Raman scattered light Lr. In the Raman spectroscopic measuring device 1, the sample S is irradiated with light L1 from a light source unit 2. The Raman scattered light Lr, which is generated by an interaction between the light L1 and the sample S, is detected by a spectroscopic device 5, and spectroscopic spectral data of the Raman scattered light Lr are acquired. By analyzing the spectral data acquired by the spectroscopic device 5 with a computer 6, various physical properties such as the molecular structure, crystallinity, orientation, and degree of distortion of the sample S can be evaluated.Examples of probe S include semiconductor materials, polymers, cells, and pharmaceuticals.

[0024] As in Fig. As shown in Figure 1, the Raman spectroscopic measuring device 1 comprises the light source unit 2, a light-guiding optical system 3, a spectroscopic optical system 4, the spectroscopic device 5, the computer 6, and a display unit 7. In the following description, the light incident on the spectroscopic device 5 through the spectroscopic optical system 4 is referred to, for simplicity, as light L1 to distinguish it from the Raman scattered light Lr. In the spectroscopic device 5, which is integrated into the Raman spectroscopic measuring device 1, light L1 refers to the Raman scattered light Lr.

[0025] The light source unit 2 is a component that generates light L0, which is used to irradiate the sample S. The light source forming the light source unit 2 can be, for example, a laser light source serving as the excitation light source for Raman spectroscopy, a light-emitting diode, or a similar device. The light-guiding optical system 3 is a component that directs the Raman scattered light Lr, generated by irradiating the sample S with light L0, to the spectroscopic device 5. The light-guiding optical system 3 includes, for example, a collimating lens, one or more mirrors, a slit, and the like.

[0026] The spectroscopic optical system 4 is a component that resolves the light L1 in a predetermined wavelength direction. The spectroscopic optical system 4 comprises a spectroscopic element that scatters the light L1 in a predetermined wavelength resolution direction. For example, a prism, a diffraction grating, a concave diffraction grating, a crystalline spectroscopic element, or similar device can be used as the spectroscopic element. The Raman scattered light Lr is scattered by the spectroscopic optical system 4 and fed into the spectroscopic device 5.

[0027] In Fig. In one case, the spectroscopic optical system 4 is configured separately from the spectroscopic device 5, but the spectroscopic optical system 4 can be incorporated as a constituent element of the spectroscopic device 5. That is, the spectroscopic device 5 can also include the spectroscopic optical system 4 with a spectroscopic element that scatters the light L1 in the wavelength resolution direction. In this case, the spectroscopic device 5 is equipped with a wavelength resolution function for the light L1, thus improving its usability. The spectroscopic device 5 is a component that receives the light L1 with wavelength resolution in a predetermined direction in order to output spectroscopic spectral data of the light L1.In the present embodiment, the spectroscopic device 5 receives the Raman scattered light Lr, which is scattered by the spectroscopic optical system 4 in a predetermined wavelength resolution direction, and outputs spectroscopic spectral data of the Raman scattered light Lr to the computer 6.

[0028] The computer 6 physically comprises a storage device such as RAM or ROM, a processor (arithmetic circuit) such as a CPU, a communication interface, and the like. For example, a personal computer, a cloud server, or a smart device (smartphone, tablet, etc.) can be used as the computer 6. The computer 6 is connected to the light source unit 2 of the Raman spectroscopic measuring device 1 and the spectroscopic device 5, enabling it to communicate information with each other and to control these constituent elements holistically. The computer 6 also functions as the analysis unit 8, which analyzes the physical properties of the sample S based on the spectral data received by the spectroscopic device 5 (generation unit 15). The computer 6 outputs information indicating the analysis result of the analysis unit 8 to the display unit 7.

[0029] As in Fig. As shown in Figure 1, the spectroscopic device 5 comprises a pixel unit 11, an accumulation unit 12, a readout unit 13, a conversion unit 14, and the generation unit 15. The pixel unit 11, the accumulation unit 12, and the readout unit 13 are configured by an imaging element 9. The conversion unit 14 comprises a semiconductor element 10. The imaging element 9 is, for example, a solid-state imaging element with a charge-coupled device (CCD). The semiconductor element 10 comprises, for example, a CMOS (Complementary Metal Oxide Semiconductor) type semiconductor chip and functions as a conversion unit 14 by means of a circuit embedded in the semiconductor chip.

[0030] In the present embodiment, the spectroscopic device 5 is configured as a camera comprising the imaging element 9, the semiconductor element 10, and the generating unit 15. Here, the spectroscopic device 5 is separate from the computer 6, but the spectroscopic device 5 can be configured to integrally include the camera, including the imaging element 9, the semiconductor element 10, and the generating unit 15, as well as the computer 6 (analysis unit 8), which is connected to the camera, so that they are able to communicate information with each other electrically or wirelessly. In this case, the computer 6 can function as the generating unit 15 and the analysis unit 8.

[0031] Fig. Figure 2 is a schematic view showing an example of a pixel unit. As in Fig. As shown in Figure 2, a plurality of pixels 21 are arranged in a row direction and a column direction perpendicular to the row direction in pixel unit 11. The row direction runs along the wavelength resolution direction of the light L1 or the Raman scattered light Lr through the spectroscopic optical system 4, and the column direction runs along a charge transfer direction of the pixel 21. Each pixel 21 receives the wavelength-resolved light L1 or the Raman scattered light Lr to generate and accumulate a charge depending on the intensity of the light.

[0032] In the example of Fig. In Figure 2, pixel unit 11 has a horizontally elongated shape where the number of pixels in the row direction is greater than the number of pixels in the column direction. Five spectroscopic images 31 (31A to 31E from the shortwave side) are created with respect to pixel unit 11. Each of the spectroscopic images 31A to 31E extends linearly in the column direction of pixel 21 and is formed on pixel unit 11 in a state where they are separated from each other in the row direction. In this case, for example, as in Fig. Figure 3 shows that the spectroscopic spectral data 32 (32A to 32E), corresponding to the spectroscopic spectral images 31A to 31E, are generated in the spectroscopic device 5. The generated spectroscopic spectral data 32 (32A to 32E) are output by the spectroscopic device 5 (generation unit 15) to the computer 6.

[0033] As described above, the imaging element 9 comprises the pixel unit 11, the accumulation unit 12, and the readout unit 13. The pixel unit 11 is a part that captures the spectroscopic spectral image 31 of the light L1 or the Raman scattered light Lr formed by the spectroscopic optical system 4. In the present embodiment, as shown in Fig. 4 and Fig. As shown in Figure 5, the image element 9 comprises a first pixel unit 11A and a second pixel unit 11B, which are divided in the column direction. The first pixel unit 11A and the second pixel unit 11B are divided in the middle in the column direction (see Figure 5). Fig. 2) That is, pixel 21 on one side of the center in the column direction belongs to the first pixel unit 11A, and pixel 21 on the other side of the center in the column direction belongs to the second pixel unit 11B.

[0034] Imaging element 9 contains a conversion substrate 40 for a control pad that controls the transfer of charges in the first pixel unit 11A and the second pixel unit 11B. The conversion substrate 40 is arranged, for example, next to pixel unit 11 along the column direction. A voltage signal (drive voltage) for controlling the transfer of charges from pixel 21 is applied to the conversion substrate 40. The charge of pixel 21 in each column belonging to the first pixel unit 11A is transferred in the direction of arrow A1. Fig. 4 along the column direction based on the voltage signal supplied to the conversion substrate 40. The charge of pixel 21 of each column belonging to the second pixel unit 11B is transferred in the direction of arrow A2 in Fig. 5 (direction opposite to arrow A1) along the column direction based on the voltage signal supplied to the conversion substrate 40.

[0035] The accumulation unit 12 is a part that accumulates the charges generated in the pixels 21 of each column. The accumulation unit 12 is arranged for each column at an end section in the column direction of the pixel unit 11. In the present embodiment, the imaging element 9 comprises a first accumulation unit 12A (see Fig. 4), which corresponds to the first pixel unit 11A, and a second accumulation unit 12B (see Fig. 5), corresponding to the second pixel unit 11B. The first accumulation unit 12A is located for each column at an end section in the column direction of the first pixel unit 11A and accumulates charges generated in the pixels 21 of each column belonging to the first pixel unit 11A. The second accumulation unit 12B is located for each column at an end section in the column direction of the second pixel unit 11B and accumulates charges generated in the pixels 21 of each column belonging to the second pixel unit 11B. The first accumulation unit 12A is located at a first end section of the pixel unit 11 in the column direction (an end section on the side of the first pixel unit 11A), and the second accumulation unit 12B is located at a second end section of the pixel unit 11 in the column direction (an end section on the side of the second pixel unit 11B) (see Fig. 2).

[0036] As in Fig. As shown in Figure 6, the accumulation unit 12 contains a floating gate electrode 41. The charge of a potential well 42 of pixel 21 in each column is transferred via a control gate electrode 43 to a final potential well 42F in each column. Charges corresponding to the number of pixels set for each column are accumulated in the final potential well 42F. When the charges corresponding to the number of pixels set have accumulated in the final potential well 42F, a voltage is output at a read node 44 via the floating gate electrode 41 to the read unit 13. After output, a reset voltage is applied to a reset transistor 45, and the charges accumulated in the final potential well 42F are removed via the reset transistor 45.

[0037] The readout unit 13 is a part that outputs an electrical signal for each column corresponding to the magnitude of the charges accumulated in the accumulation unit 12. In the present embodiment, the imaging element 9 comprises a plurality of first readout units 13A, each corresponding to the first accumulation unit 12A, and a plurality of second readout units 13B, each corresponding to the second accumulation unit 12B. The first readout unit 13A is arranged in the subsequent stage of the first accumulation unit 12A at the first end section of the pixel unit 11 in the column direction (the end section on the side of the first pixel unit 11A), and the second readout unit 13B is arranged in the subsequent stage of the second accumulation unit 12B at the second end section of the pixel unit 11 in the column direction (the end section on the side of the second pixel unit 11B) (see Fig. 2) The first readout unit 13A outputs a first electrical signal for each column, corresponding to the magnitude of the charges accumulated in the first accumulation unit 12A. The second readout unit 13B outputs a second electrical signal for each column, corresponding to the magnitude of the charges accumulated in the second accumulation unit 12B.

[0038] As in Fig. As shown in Figure 4, the first readout unit 13A contains a transistor 51A and a connection pad 52A for signal output. A control terminal (gate) of transistor 51A is electrically connected to the first accumulation unit 12A. A current terminal (drain) of transistor 51A is electrically connected via a wiring connection 53A, which is provided across each column of the first pixel unit 11A, to a connection pad 54A. A voltage of a predetermined value is always applied to the connection pad 54A.

[0039] The other current terminal (source) of transistor 51A is electrically connected to the signal output pad 52A. A voltage corresponding to the first electrical signal output by the first accumulator unit 12A is applied to the control terminal of transistor 51A. A current corresponding to the applied voltage is output from the other current terminal of transistor 51A and routed via the signal output pad 52A. The first electrical signal output by the signal output pad 52A is amplified by an amplifier 55 (see Fig. 6) amplified and then output to conversion unit 14.

[0040] As in Fig. As shown in Figure 5, the second readout unit 13B contains a transistor 51B and a connection pad 52B for signal output. A control terminal (gate) of transistor 51B is electrically connected to the second accumulation unit 12B. A current terminal (drain) of transistor 51B is electrically connected to a bonding pad 54B via a common wire 53B that runs across each column of the second pixel unit 11B. A voltage of a predetermined magnitude is always applied to the bonding pad 54B.

[0041] The other current terminal (source) of transistor 51B is electrically connected to the signal output pad 52B. A voltage corresponding to the second electrical signal output by the second accumulator 12B is applied to the control terminal of transistor 51B. A current corresponding to the applied voltage is output from the other current terminal of transistor 51B and routed via the signal output pad 52B. The second electrical signal output by the signal output pad 52B is amplified by amplifier 55 (see Fig. 6) amplified and then output to conversion unit 14.

[0042] The conversion unit 14 is a part that converts the electrical signal of each column, output by the readout unit 13, into a digital signal and outputs the digital signal. In the present embodiment, as shown in Fig. 7 and Fig. As shown in Figure 8, the semiconductor element 10 contains a plurality of first conversion units 14A, each corresponding to the first readout unit 13A, and a plurality of second conversion units 14B, each corresponding to the second readout unit 13B. The first conversion unit 14A converts a first electrical signal from each column output by the first readout unit 13A into a digital signal and outputs the digital signal. The second conversion unit 14B converts a second electrical signal from each column output by the second readout unit 13B into a digital signal and outputs the digital signal. The semiconductor element 10 can separately contain a first semiconductor element forming the first conversion unit 14A and a second semiconductor element forming the second conversion unit 14B.

[0043] As in Fig. As shown in Figure 7, the first conversion unit 14A comprises a bond pad 61A, a CDS circuit 62A, a buffer 63A, an A / D converter circuit 64A, and a multiplexer 65A. The contact pad 61A is electrically connected to the connection pad 52A for the signal output of the first readout unit 13A. The CDS circuit 62A reduces the noise of the first electrical signal input from the contact pad 61A. The buffer 63A amplifies the first electrical input signal from the CDS circuit 62A. The A / D converter circuit 64A converts the first electrical input signal from the buffer 63A into a first digital signal. The multiplexer 65A outputs the first digital signal of each column, input from each A / D converter circuit 64A, to the generation unit 15.

[0044] As in Fig. As shown in Figure 8, the second conversion unit 14B contains a bond pad 61B, a CDS circuit 62B, a buffer 63B, an A / D converter circuit 64B, and a multiplexer 65B. The bond pad 61B is electrically connected to the terminal pad 52B for the signal output of the second readout unit 13B. The CDS circuit 62B reduces the noise of the second electrical signal input from the bond pad 61B. The buffer 63B amplifies the second electrical input signal from the CDS circuit 62B. The A / D converter circuit 64B converts the second electrical input signal from the buffer 63B into a second digital signal. The multiplexer 65B outputs the second digital signal of each column, input from each A / D converter circuit 64B, to the generation unit 15.

[0045] In the present embodiment, in the imaging element 9, a first exposure time T1 of each pixel 21 belonging to the first pixel unit 11A and a second exposure time T2 of each pixel 21 belonging to the second pixel unit 11B are different from each other. In particular, as shown in Fig. As shown in Figure 9, the first exposure time T1 of each pixel 21 belonging to the first pixel unit 11A is shorter than the second exposure time T2 of each pixel 21 belonging to the second pixel unit 11B. Therefore, image data from a multitude of individual frames in the first pixel area 21A are acquired during a period in which image data from a single frame in the second pixel area 21B is acquired. In the example of Fig. 9, where the second exposure time T2 is an integer multiple of the first exposure time T1. In this example, image data of a frame that is an integer multiple of the second pixel unit 11B is captured in the first pixel unit 11A during a period in which image data of a frame in the second pixel unit 11B is captured.

[0046] The generating unit 15 is physically configured by a computer system that includes a storage device such as RAM or ROM, a processor (computing circuit) such as a CPU, a communication interface, and the like. The generating unit 15 may contain a programmable logic controller (PLC) and a field-programmable gate array (FPGA).

[0047] The generating unit 15 generates initial spectroscopic data based on the first digital signal input from the first conversion unit 14A. It also generates a second set of spectroscopic data based on the second digital signal input from the second conversion unit 14B. The initial spectroscopic data is acquired in the first pixel unit 11A with a relatively short initial exposure time T1 and is, for example, equal to or less than a saturation level in all wavelength bands. The second set of spectroscopic data is acquired in the second pixel unit 11B with a relatively long second exposure time T2 and is, for example, equal to or greater than a saturation level in a specific wavelength band.

[0048] The generating unit 15 divides the wavelength band of the entire spectrum into a saturation wavelength band and a non-saturation wavelength band of the second spectroscopic spectral data. In the saturation wavelength band, the second spectroscopic spectral data are equal to or greater than the saturation level, and the first spectroscopic spectral data are less than the saturation level. In the non-saturation wavelength band, the second spectroscopic spectral data are less than the saturation level and have a more favorable signal-to-noise ratio than the first spectroscopic spectral data. The generating unit 15 combines the first spectroscopic spectral data in the saturation wavelength band and the second spectroscopic spectral data in the non-saturation wavelength band to generate spectroscopic spectral data that are output to the computer 6.

[0049] Fig. Figure 10 is a flowchart illustrating a spectroscopic method according to an embodiment of the present disclosure. This spectroscopic method is a method for receiving light that is wavelength-resolved in a predetermined direction in order to acquire spectroscopic spectral data of the light. The spectroscopic method according to the present embodiment is carried out using the spectroscopic device 5 described above. As in Fig. As shown in Figure 10, this spectroscopic method comprises a light reception step (step S01), an accumulation step (step S02), a readout step (step S03), a conversion step (step S04), a generation step (step S05) and an analysis step (step S06).

[0050] In the light reception step S01, the wavelength-resolved light L1 or the Raman scattered light Lr is received by the plurality of pixels 21, which are arranged in the row direction along the wavelength resolution direction and in the column direction perpendicular to the row direction. In the present embodiment, the light L1 or the Raman scattered light Lr is received in different exposure periods in the first pixel unit 11A and the second pixel unit 11B.

[0051] In the accumulation step S02, the charges generated in the pixels 21 of each column are accumulated. In the present embodiment, the first accumulation unit 12A accumulates charges generated in the pixels 21 of each column belonging to the first pixel unit 11A, and the second accumulation unit 12B accumulates charges generated in the pixels 21 of each column belonging to the second pixel unit 11B. When charges corresponding to the number of pixels set for each column are accumulated in the final potential well 42F, the first accumulation unit 12A and the second accumulation unit 12B output a voltage at the read node 44 via the floating gate electrode 41 to the readout unit 13. Afterwards, a reset voltage is applied to the reset transistor 45, and the charges accumulated in the final potential well 42F are removed via the reset transistor 45.

[0052] In readout step S03, an electrical signal corresponding to the magnitude of the accumulated charges is output for each column. In the present embodiment, the first readout unit 13A outputs the first electrical signal of each column, corresponding to the magnitude of the charges accumulated in the first accumulation unit 12A, and the second readout unit 13B outputs the second electrical signal of each column, corresponding to the magnitude of the charges accumulated in the second accumulation unit 12B. The first electrical signal of each column and the second electrical signal of each column are amplified by the amplifier 55 and then output to the conversion unit 14.

[0053] In conversion step S04, the electrical signal of each column is converted into a digital signal, and the digital signal is output. In the present embodiment, the first conversion unit 14A converts the first electrical signal of each column, output by the first readout unit 13A, into the first digital signal of each column and outputs the first digital signal, and the second conversion unit 14B converts the second electrical signal of each column, output by the second readout unit 13B, into the second digital signal of each column and outputs the second digital signal. The first digital signal of each column, converted from the first electrical signal of each column by the A / D converter circuit 64A, and the second digital signal of each column, converted from the second electrical signal of each column by the A / D converter circuit 64B, are output to the generation unit 15.

[0054] In generation step S05, the spectroscopic spectral data 32 are generated based on the digital signal. In the present embodiment, the generation unit 15 generates the first spectroscopic spectral data based on the first digital signal and the first spectroscopic spectral data based on the second digital signal. The generation unit 15 combines the first spectral data in the saturation wavelength band and the second spectroscopic data in the non-saturation wavelength band to generate the spectroscopic spectral data 32, which are output to the computer 6. The generated spectroscopic spectral data 32 are output to the analysis unit 8.

[0055] In analysis step S06, the sample S is analyzed based on the spectroscopic spectral data 32 generated in production step S05. For example, the waveform, peak position, half-width, and the like of the spectroscopic spectrum are analyzed to evaluate various physical properties such as the molecular structure, crystallinity, orientation, and distortion amount of the sample S.

[0056] As described above, in the spectroscopic device 5, the wavelength-resolved light L1 is received by the plurality of pixels 21 arranged in the row and column directions. Charges generated in the pixels 21 of each column are accumulated, and then an electrical signal corresponding to the magnitude of the charges is output for each column. Since these processes are performed by the CCD imaging element 9, it is possible to avoid an increase in readout noise when reading the charges generated in the pixels 21 of each column. Furthermore, the readout speed when outputting the digital signal based on the electrical signal of each column is faster than if a horizontal transmission circuit were used, and the noise caused by heat generation is also suppressed.Therefore, the spectroscopic spectral data 32 can be acquired in the spectroscopic device 5 with an excellent SN ratio.

[0057] In the spectroscopic device 5, the imaging element 9 comprises the first pixel unit 11A and the second pixel unit 11B, which are subdivided in the column direction; the first accumulation unit 12A and the second accumulation unit 12B, wherein the first accumulation unit for each column is arranged at an end section in the column direction of the first pixel unit 11A and accumulates charges generated in the pixels 21 of each column; and the second accumulation unit for each column is arranged at an end section in the column direction of the second pixel unit 11B and accumulates charges generated in the pixels 21 of each column; and the first readout unit 13A and the second readout unit 13B, wherein the first readout unit outputs the first electrical signal corresponding to a magnitude of the charges accumulated in the first accumulation unit 12A.and the second readout unit outputs the second electrical signal corresponding to the magnitude of the charges accumulated in the second accumulation unit 12B.

[0058] Furthermore, the semiconductor element 10 contains the first conversion unit 14A, which converts the first electrical signal of each column, output by the first readout unit 13A, into a digital signal and outputs the digital signal, and the second conversion unit 14B, which converts the second electrical signal of each column, output by the second readout unit 13B, into a digital signal and outputs the digital signal. This allows the first pixel unit 11A and the second pixel unit 11B to be used selectively according to the mode of the spectroscopic spectral image 31. Therefore, the spectroscopic spectral data 32 of different light sources can be acquired with a favorable SN ratio.

[0059] In the spectroscopic apparatus 5, the first exposure time T1 of each pixel 21 belonging to the first pixel unit 11A is shorter than the second exposure time T2 of each pixel 21 belonging to the second pixel unit 11B. According to this configuration, for example, spectroscopic spectral images 31 of light L1 with different intensities depending on the wavelengths can be acquired at different exposure times in the first pixel unit 11A and the second pixel unit 11B.In the present embodiment, by combining a saturation wavelength band of the first spectroscopic spectral data, which were acquired with the relatively short exposure time T1 in the first pixel unit 11A, and a non-saturation wavelength band of the second spectroscopic spectral data, which were acquired with the relatively long exposure time T2 in the second pixel unit 11B, the spectroscopic spectral data 32 can be acquired with a favorable SN ratio in a high dynamic range.

[0060] In the Raman spectroscopic measuring device 1, configured by incorporating the spectroscopic device 5 described above, the wavelength-resolved Raman scattered light Lr is received by the plurality of pixels 21 arranged in the row and column directions. Charges generated in the pixels 21 of each column are accumulated, and then an electrical signal is output for each column corresponding to the magnitude of the charges. Since these processes are performed by the CCD imaging element 9, it is possible to avoid an increase in readout noise when reading out the charges generated in the pixels 21 of each column. Furthermore, the readout speed for outputting the digital signal based on the electrical signal of each column is faster than when using a horizontal transmission circuit, and the noise caused by heat generation is also suppressed.Therefore, the spectroscopic spectral data 32 can be acquired with an excellent SN ratio in the Raman spectroscopic measuring device 1.

[0061] The present disclosure is not limited to the embodiment above, and various modifications may be applied. In the embodiment, for example, the image element 9 comprises the first pixel unit 11A and the second pixel unit 11B, which are subdivided in the column direction, but the first pixel unit 11A and the second pixel unit 11B may also be subdivided in the row direction, as shown in Fig. 11 shown. Fig. 11 contains the mapping element 9 similar to that in Fig. 2 the first accumulation unit 12A and the second accumulation unit 12B, wherein the first accumulation unit is arranged for each column at an end section in the column direction of the first pixel unit 11A and accumulates charges generated in the pixels 21 of each column, and the second accumulation unit is arranged for each column at an end section in the column direction of the second pixel unit 11B and accumulates charges generated in the pixels 21 of each column. Furthermore, the mapping element 9 comprises the first readout unit 13A and the second readout unit 13B, wherein the first readout unit outputs the first electrical signal of each column corresponding to a magnitude of the charges accumulated in the first accumulation unit 12A, and the second readout unit outputs the second electrical signal of each column corresponding to a magnitude of the charges accumulated in the second accumulation unit 12B.

[0062] In the example of Fig. In example 11, both the first accumulation unit 12A and the second accumulation unit 12B are arranged along an end section of the pixel unit 11 in the column direction. Both the first readout unit 13A and the second readout unit 13B are arranged at the same end section in the subsequent stage of the first accumulation unit 12A and the second accumulation unit 12B. That is, in the example of Fig. 11 a charge transfer direction of pixel 21 belonging to the first pixel unit 11A, and a charge transfer direction of pixel 21 belonging to the second pixel unit 11B, are the same direction (both are the arrow direction A3).

[0063] In the present embodiment, the first readout unit 13A and the second readout unit 13B are provided for each column at an end section in the column direction of each pixel 21 in the pixel unit 11. Therefore, the time of charge removal and the application of the reset voltage can also be changed for each column. Here, the first exposure time T1 of each pixel 21 belonging to the first pixel unit 11A and the second exposure time T2 of each pixel 21 belonging to the second pixel unit 11B are the same.On the other hand, the first readout unit 13A outputs the first electrical signal of each column at a stage in which charges generated in the pixels 21 corresponding to a first number of rows are accumulated in the first accumulation unit 12A, and the second readout unit 13B outputs the second electrical signal of each column at a stage in which charges generated in the pixels 21 corresponding to a second number of rows, which is smaller than the first number of rows, are accumulated in the second accumulation unit 12B.

[0064] This means that for the pixels 21 of each column belonging to the first pixel unit 11A, the first electrical signal is output after a relatively large amount of charge has accumulated in the final potential well 42F, and the number of charge resets is relatively reduced. Furthermore, for the pixels 21 of each column belonging to the second pixel unit 11B, the second electrical signal is output after a relatively small amount of charge has accumulated in the final potential well 42F, and the number of charge resets is relatively increased. Even in such a configuration, the first pixel unit 11A and the second pixel unit 11B can be used selectively according to the mode of the spectroscopic spectral image 31. Therefore, the spectroscopic spectral data 32 of different types of light L1 can be acquired with a favorable SN ratio.

[0065] As in Fig. Figure 12 shows, for example, a case is considered in which light with a spectrum in which the signal intensity on the short-wavelength side is relatively weak and the signal intensity on the long-wavelength side is relatively strong, is fed into the spectroscopic device 5 in a wavelength-resolved state. In this case, it is conceivable that if the spectroscopic spectral image of the wavelength-resolved light is acquired in a single pixel unit with a constant exposure time, the overall spectral data on the short-wavelength side are not saturated, but the signal-to-noise ratio cannot be sufficiently maintained, and the spectral data on the long-wavelength side exhibit a favorable signal-to-noise ratio overall, but the spectral data are saturated at a wavelength of a predetermined intensity or higher.

[0066] On the other hand, in the example of Fig. For example, the spectroscopic images 31A to 31C on the shortwave side are acquired by the first pixel unit 11A, and the spectroscopic images 31D and 31E on the longwave side are acquired by the second pixel unit 11B. Furthermore, for the pixels 21 of each column belonging to the first pixel unit 11A, the first electrical signal is output after a relatively large amount of charge has accumulated in the final potential well 42F, and for the pixels 21 of each column belonging to the second pixel unit 11B, the second electrical signal is output after a relatively small amount of charge has accumulated in the final potential well 42F.

[0067] In this case, as in Fig. As shown in Figure 13, the generating unit 15 produces the first spectral data on the shortwave side and the second spectral data on the longwave side. In the first spectral data, the sensitivity for the spectroscopic spectral images 31A to 31C is improved, and the SN ratio is improved, by outputting the first electrical signal after a relatively large amount of charge has accumulated. In the second spectral data, saturation can be suppressed by outputting the second electrical signal after a relatively small amount of charge has accumulated. Therefore, as shown in Fig. Figure 14 shows that by combining the first spectral data and the second spectral data to generate final spectroscopic spectral data, spectroscopic spectral data with a favorable SN ratio can be acquired in a high dynamic range.

[0068] In general, the spectroscopic spectral images 31 (31A to 31E), as in Fig. 2 is shown, formed symmetrically with respect to the center of pixel unit 11 in the column direction. As in Fig. As shown in Figure 15, the spectroscopic spectral images 31 (31A to 31E) can be formed at a position shifted in the slit direction from the center of the pixel unit 11. It is assumed that the spectroscopic spectral image 31 actually formed on the pixel unit 11 by the spectroscopic optical system 4 is non-linear due to the influence of the optical system's aberration, as is the case, for example, in Czerny-Turner spectroscopy.

[0069] In the example of Fig. In 15, the spectroscopic image 31C, located at the center of pixel unit 11, has a linear shape in the slit direction. However, in each of the spectroscopic images 31A and 31B, and in the spectroscopic images 31D and 31E, a so-called pincushion distortion occurs, in which the image is curved towards the center of pixel unit 11. The degree of distortion of the spectroscopic image 31 increases the further the spectroscopic image is from the center of pixel unit 11. The degree of distortion of the spectroscopic images 31A and 31E is greater than the degree of distortion of the spectroscopic images 31B and 31D.

[0070] In such a case, as in Fig.As shown in Figure 15, by forming the spectroscopic images 31A to 31E, which are shifted in the column direction from the center of the pixel unit 11, it is possible to exclude a portion of the image with a large distortion from the representation of the spectroscopic images 31A to 31E. This makes it possible to suppress a reduction in the wavelength resolution in the row direction in each of the spectroscopic data 32A to 32E generated based on the distortion, even if the spectroscopic images 31A to 31E are distorted. Furthermore, a reduction in the peak value is also suppressed, and the S-n ratio is improved.

[0071] As a further modification, the pixel unit 11 need not necessarily be divided into the first pixel area 21A and the second pixel area 21B and can be configured by a single pixel area. The spectroscopic device 5 is not limited to the Raman spectroscopic measuring device 1, but can also be applied to other spectroscopic measuring devices such as a fluorescence spectroscopic measuring device, a plasma spectroscopic measuring device, and an emission spectroscopic measuring device. Furthermore, the spectroscopic device 5 can also be used for other spectroscopic measuring devices, such as a device for measuring layer thickness, optical density, laser-induced breakthrough spectroscopy (LIBS), and differential optical absorption spectroscopy (DOAS). List of reference symbols 1 Raman spectroscopic measuring device 2 light source units 3 Light-guiding optical system 4 Spectroscopic optical system 5 Spectroscopic device 8 analysis units 9 Image element 10 Semiconductor element 11 pixel units 11A first pixel unit 11B second pixel unit 12 accumulation units 12A first accumulation unit 12B second accumulation unit 13 Reading unit 13A first readout unit 13B second readout unit 14 conversion unit 14A first conversion unit 14B second conversion unit 15 production units 31 (31A to 31E) spectroscopic spectral image 32(32A to 32E) spectroscopic spectral data L1 light Lr Raman scattered light T1 first exposure time T2 second exposure time QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2016-180732

[0003]

Claims

[1] A spectroscopic device that receives wavelength-resolved light in a predetermined direction through a spectroscopic optical system containing a spectroscopic element to acquire spectroscopic spectral data of the light, the spectroscopic device comprising: a CCD-type imaging element with: a pixel unit having a plurality of pixels arranged in a row direction along a wavelength resolution direction of the light and in a column direction perpendicular to the row direction, an accumulation unit arranged for each column at an end portion in the column direction of the pixel unit and accumulating charges generated in pixels of each column, and a readout unit that outputs an electrical signal for each column corresponding to a magnitude of the charges accumulated in the accumulation unit; a semiconductor element that converts the electrical signal of each column output by the readout unit into a digital signal and outputs the digital signal; and a generating unit that generates spectroscopic spectral data based on the digital signal output from the semiconductor element. [2] The spectroscopic device according to claim 1, wherein the imaging element comprises: a first pixel unit and a second pixel unit divided in the column direction, a first accumulation unit and a second accumulation unit, wherein the first accumulation unit for each column is arranged at an end portion in the column direction of the first pixel unit and accumulates charges generated in pixels of each column, and the second accumulation unit for each column is arranged at an end portion in the column direction of the second pixel unit and accumulates charges generated in pixels of each column, and a first readout unit and a second readout unit, wherein the first readout unit outputs a first electrical signal for each column corresponding to a size of the charges accumulated in the first accumulation unit, and the second readout unit outputs a second electrical signal for each column corresponding to a size of the charges accumulated in the second accumulation unit, and the semiconductor element comprises: a first conversion unit that converts the first electrical signal of each column output from the first readout unit into a digital signal and outputs the digital signal, and a second conversion unit that converts the second electrical signal of each column output from the second readout unit into a digital signal and outputs the digital signal. [3] The spectroscopic device according to claim 2, wherein a first exposure time of each pixel belonging to the first pixel unit is shorter than a second exposure time of each pixel belonging to the second pixel unit. [4] The spectroscopic apparatus according to claim 3, wherein image data of a plurality of frames are acquired in the first pixel unit during a period in which image data of one frame is acquired in the second pixel unit. [5] The spectroscopic device according to claim 1, wherein the imaging element comprises: a first pixel unit and a second pixel unit divided in the row direction, a first accumulation unit and a second accumulation unit, wherein the first accumulation unit for each column is arranged at an end portion in the column direction of the first pixel unit and accumulates charges generated in pixels of each column, and the second accumulation unit for each column is arranged at an end portion in the column direction of the second pixel unit and accumulates charges generated in pixels of each column, and a first readout unit and a second readout unit, wherein the first readout unit outputs a first electrical signal for each column corresponding to a size of the charges accumulated in the first accumulation unit, and the second readout unit outputs a second electrical signal for each column corresponding to a size of the charges accumulated in the second accumulation unit. [6] The spectroscopic device according to claim 5, wherein the first readout unit outputs the first electrical signal of each column at a stage where charges generated in pixels corresponding to a first number of rows are accumulated in the first accumulation unit, and the second readout unit outputs the second electrical signal of each column at a stage where charges generated in pixels corresponding to a second number of rows smaller than the first number of rows are accumulated in the second accumulation unit. [7] The spectroscopic device according to any one of claims 1, 2 and 5, further comprising an analysis unit that analyzes the spectroscopic spectral data. [8] The spectroscopic device according to any one of claims 1, 2 and 5, further comprising the spectroscopic optical system with the spectroscopic element. [9] A Raman spectroscopic measuring device comprising: the spectroscopic device according to any one of claims 1, 2 and 5; a light source unit that generates light with which a sample is irradiated; and an optical light guide system that directs the Raman scattered light generated by irradiating the sample with light to the spectroscopic device. [10] A spectroscopic method for receiving light that is wavelength-resolved in a predetermined direction to acquire spectroscopic spectral data of the light, the spectroscopic method comprising: a light receiving step for receiving the wavelength-resolved light by a plurality of pixels arranged in a row direction along a wavelength resolution direction and in a column direction perpendicular to the row direction; an accumulation step for accumulating charges generated in pixels of each column; a readout step for outputting an electrical signal for each column corresponding to a quantity of the accumulated charges; a conversion step for converting the electrical signal of each column into a digital signal and outputting the digital signal; and a generation step for generating spectroscopic spectral data based on the digital signal.

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